Marine through-transom propulsion unit



c. E. MACDONALD ETAL 3,368,517

MARINE THROUGH-TRANSOM PROPULSION UNIT Feb. 13, 1968 4 Sheets-Sheet 1 Filed Sept. 21, '1959 at; MACDONALD .1. w. ANDERSON JERRY Ian/z cg AETORNEYS Feb. 13, 1968 c. E. MACDONALD ET AL 3,368,517

MARINE THROUGHTTRANSOM PROPULSION UNI T.

Filed Sept. 21, 1959 4 Sheets-Sheet 2 em 1 m mmw o 96 E m INVENTOR .c. E. "A coo/mm I 58 I. 56 JJMANDERSON ATTORNEYS Feb. 13, 19-68 c, MACDONALD ET AL 3,368,517

MARINE THROUGH-TRANSOM PROPULSION UNIT Filed Sept. 21, 1959 1 4 Sheets-Sheet 5 z I g a I I, r l 8I/\/\/77 2 z 7e-- I I 78* i I i x as g8 v i t 1 86 4,4 4 & J

L i I l l a i i 1 W 5 i I 75 :1 5 I INVENTOR r f (7 5. MACDONALD .l. M. 011/0528 0N ATTQRNEY$ Feb. 13, 1968 c, E, MACDONALD ET AL MARINE THROUGH-TRANSOM PROPULSION UNIT 4 Sheets-Sheet 4 Filed Sept. 21, 1959 s R Y W? ,O N J .w I N R m A 5 Cw LN 0 Ci BY WQVQZMQ a #l i 1 .1 ZQMQY United States Patent 3,368,517 MARINE THROUGH-TRANSOM PROPULSIUN UNIT Charles E. Macrlonald, John W. Anderson, and Jerry C. Barker, Seattle, Wash, assignors, by inesne assignments, to Eaton Yale & Towne Inc., a corporation of Ohio Filed Sept. 21, 1959, Ser. No. 841,105 11 Claims. (Cl. 115-41) This invention relates to improvements in marine propulsion units of the through transom type, i.e., a unit having an inboard engine passing its drive through an opening in the boat transom to the head end of an outboard power leg in which the drive is passed downwardly to a propeller carried on the lower end of the leg.

A principal object of the invention is to provide a unit of this type in which the power leg will swing upwardly when it engages an obstruction apt to damage it, and yet will operate in a reverse drive condition without kicking Another object is to provide a through-transom marine propulsion unit in which the outboard portion thereof can be easily removed from the boat.

The invention further aims to provide an arrangement wherein the power leg not only swings upwardly upon engagement with an obstruction, but can also be easily manually turned up about a fore and aft axis as, for example, when it is desired to transport the boat out of water.

Other objects and advantages looking to the general perfection of a through-transom drive will, with the foregoing, appear and be understood in the course of the following description and claims, the invention consisting in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings:

FIGURE 1 is a fragmentary longitudinal vertical sectional view with parts in elevation, illustrating a throughtransom drive constructed to embody the preferred teachings of the present invention.

FIG. 2 is a fragmentary side elevational view drawn to a reduced scale showing the power leg as it appears when the same swings upwardly to clear an obstruction.

FIG. 3 is a fragmentary transverse vertical sectional view drawn to an enlarged scale on line 33 of FIG. 1.

FIG. 4 is a detail horizontal sectional view on line 44 of FIG. 1.

FIG. 5 is a large-scale fragmentary longitudinal vertical sectional view through the gear box of the invention on substantially the same section line as FIG. 1.

FIG. 6 is a reduced-scale transverse vertical sectional view on line 66 of FIG. 5.

FIG. 7 is a top plan view of the gear box as indicated by line 77 of FIG. 1; and

FIG. 8 is a detail vertical sectional view taken as indicated by the detail circle 8 in FIG. 1.

Referring to the drawings, the numeral 9 designates the transom of a boat into which a circular opening 10 is provided well above the water-line. An inboard power plant (not shown) is permanently mounted on a suitable bed to the immediate front of the transom and its flywheel 11 has an aft spider whose hub 12 is internally splined and located in generally centered relation to the transom opening 10. The engine mount provides a centerbored tail-piece 13 which extends through the transom opening. Back-wash into the boat around the tail-piece is prevented by a rubber shield 14. A forwardly directed hollow neck 15 extends into the tail-piece 13 from a vertically elongated shell 16. This shell presents a cupped opening facing toward the rear, the upper portion thereof being shaped generally like a quarter sphere while the 3,368,517 Patented Feb. 13, 1968 lower portion presents opposed cheeks 17. A series of transversely aligned horizontal holes 18 is bored through these cheeks to receive, selectively, a stop pin 19 for setting the attack angle of the propeller unit as will later be seen.

Cooperating as the internal complement of the shell 16 is a generally hemispherical shell 20 which has a rearwardly directed neck 21 interfitting with a gear box housing 22 and rigidly secured thereto as by cap screws 23. The shells 16 and 20 collectively house a double-link universal, such universal connecting a tail shaft 24, which has a spline connection with hub 12, to an input shaft 25 for the gear box. At its aft end the tail shaft 24 is journaled by a bearing 26. The two yokes, the double link, and the two crosses of the double-link universal are denoted by 27, 28, 30, 33 and 34, respectively. To make the universal water tight there is provided an expansion mutt 35 which is clamped at the back around an annular flange 36 presented by the aft shell 20 and at the front around a member 37 carried by a flanged adapter plate which is secured to the shell 16. A rubber bumper ring 38 is held in place by said plate, its function being to prescribe a travel limit for the shell 20 as the latter swings upwardly about the center of trunnion pins 29 as an axis.

As best shown in FIG. 8, the shell 16 is selectively locked in position by a lock pin 39 which is urged by a spring 40 into a circumferential groove 41 formed in the shell neck 15 and intersected at quadrant points by radial openings 42.. The spring is housed in a bore 44 near the free end of the tail-piece 13, being compressed between a stop-flange 45 on the lock pin and a cover plate 46. The lock pin is released by action of a cam 47 which is pivotally attached at 43 to the outer end of the pin, this cam presenting three cam faces, as 47a, 47b and 470, which act when seated against the cover plate to locate the pin 39 in any one of three positions, selectively. One such position lodges the lock pin in a registering one of said four radial openings 42. When so placed the housing or shell 16 is perforce held against rotating. A second said position withdraws the pin only so far as to clear said radial opening, whereupon the shell 16 may be turned within the tail-piece 13. The third said position withdraws the pin both from the radial opening and the circumferential groove, and the neck 15 may then be slipped rearwardly out of the tail piece for bodily removal of the outboard portion of the through-transom drive. The spline interfit permits ready disengagement as between the tail shaft 24 and the driven flywheel.

Primary support for the gear box and its conventional power leg appendage 51 is obtained from a yoke 52 which has its arms 53 swung on a horizontal axis by the referral to trunnion pins 29 which are located at opposite sides of the shell 16 as shown in FIG. 3. A center leg 55 of the yoke is longitudinally bored to receive a pivot pin 56 defining the steering axis. Such axis approximately traverses the mean pivot of the universal, and we find that inclining such pin 56, as shown, greatly enhances steering ease. This pin 56 projects above and below the yoke leg to seat in bushings 57-58 provided by an intermediate support arm 60 and a bottom flange 61 on the gear box housing 22. With the described arrangement the power leg can always swing in a vertical plane about the trunnion pins 29 while being free to turn, for steering, about pin 56. In this latter regard, the top of the gear box is provided with an apertured supplementary plate 62 (FIG. 7) for receiving the fittings for steering lines 63.

With attention directed to FIG. 5, it is seen that transmission mechanism is provided in the gear box for passing power to an output shaft 64 which extends downwardly through the power leg and has driving connection from its lower end to a propeller 65. Bevel gears 66, 67 and 68 pass the drive from the input shaft to the output shaft 64, with forward and reverse selection being made by a clutch spool 70 sliding on a feathered upper end of said output shaft. A circumferential groove 71 in said clutch spool is engaged by a shipping fork 72. This fork is shifted from the neutral position illustrated in FIG. 5 responsive to manual actuation of a push-pull cable 73 sliding in a sheath 79 localized by a bracket 74. Such cable is pivotally connected at its lower end to one of two cranks '75 and 78 carried by a crank pin 76 journaled in an aft cover plate 77. The other crank connects by a wrist pin 80 with the lower end of a link 81. At its upper end this link pivotally connects at 82 with the shipping fork 72. The fork slides on a vertical guide pin 83 which is seated at its ends in a mounting ring 84 fitting in the back of the gear box.

As best seen in FIG. 6, the crank 78 has three transverse grooves in its underside to receive a ball 35 loaded by a spring 86 housed in a bore at the bottom of the cover plate 77. This arrangement provides a yielding resistance to shifting and hence holds the clutch spool in the selected position.

The gears 67-68 fit on alined sleeve prolongations 87- 88 of cross-slotted jaw complements 69 of the clutch jaws, and are drive-coupled to said jaw complements 69 by means of diametrically extending ribs which fit in said slots. The sleeve prolongations are journaled by ball-bearing asemblies 99-91. Access to the bearings is had through a top cover plate 92. The input gear 66, as above stated, is splined by an elongated hub to the tail of the shaft 25 and is journaled by a pair of ball hearing units 93 seated in the shell neck 21. It will be noted that snap-rings are provided for mounting and retaining the ball bearing units. The output shaft is necked above its feathered end to receive a bearing 94 seated at the lower end of the upper gear sleeve 87 and is also provided with an intermediate bearing 95 at the bottom of the gear box.

When the power leg is in its down position the yoke leg 55 rests against the adjustable stop pin 19, and hence the position of the latter selected holes 18 determines the attack an le of the propeller 65. Resistance is provided to up-tilting of the power leg during reverse turning of the propeller by means of latch arms 96 which hook beneath the stop pin 19, as best observed in FIG. 1. These latch arms are connected at the rear by an integral cross-member 97 which is urged downwardly by an anchored spring 98 to responsively swing the hook ends of the arms upwardly about a pivot pin 100. This pin is in turn carried by a pair of yoked lever arms 191 which are pivoted at 102 to the back of the leg 55 and are urged rearwardly by a spring 103 acting on the crossmember 104 which extends between the upper ends of the levers. Up-swing of the latch arms 96 is limited by laterally projecting ends of a pin 105 anchored in said leg 55.

The resistance of the latch arms 96 to release from the stop-pin 19 is adjusted to resist normal reverse torque but at the same time is light enough to readily release if the power leg strikes an obstruction. When such occurs the spring 103 compresses sufficiently to permit the hooking end of the latch arms 96 to be moved downwardly and backwardly free of the stop pin 19. Then the power leg flips up to clear the obstruction. During this tilting operation the power to the propeller continues without interruption and upon clearing the obstruction the power leg drops by its own weight to operating position, the latch arms resuming their locking position as their front ramp faces 106 ride over the lock pin 19.

It is thought that the invention will have been clearly understood from the foregoing detailed description of my now-preferred illustrated embodiment. Changes in the details of construction may be resorted to without departing from the spirit of the invention and it is accordingly my intention that the hereto annexed claims be given a scope fully commensurate with the broadest interpretation to which the employed language admits.

What I claim is:

1. In a through-transom drive, in combination with a boat hull having a transom and an inboard motor, a mounting member anchored to said hull forwardly of said transom and presenting a hollow portion extending rearwardly through said transom, a hollow rearwardly open shell member interlitting with said hollow portion and occupying a position behind said transom, mounting apparatus pivotally mounted on said shell member for fore and aft swinging movement toward and away from said transom, an outboard power leg carrying a propeller at its lower end and pivotally mounted on said mounting apparatus for lateral steering movement relative to said hull, and drive means for transferring power from said inboard motor through said mounting member and shell member to said propeller via said power leg, said drive means including universal joint means located between the transom and the power leg and extending through said mounting apparatus, said power leg presenting a forwardly open shell member which interfits with the rearwardly open shell member and with the latter produces a guard housing investing the universal joint means, said composite guard housing having much the appearance of a ball when viewed from above, the pivot mounting for the mounting apparatus being located on a substantial diameter of the ball.

2. In a through-transom drive, in combination with a boat hull having a transom and an inboard motor, a mounting member fixedly associated with said hull and presenting a rearwardly open guard shell behind said transom, mounting apparatus having a pivotal mount on said guard shell for fore and aft swinging movement relative to the hull, an outboard power leg carrying a propeller at its lower end and pivotally mounted on said mounting apparatus for lateral steering movement relative to said hull, said power leg presenting a forwardly open guard shell meshing with the afore-mentioned guard shell, universal joint means protectively housed in said guard shells, and means for transferring power through said transom from said motor to said universal joint means and from the latter to said propeller via said power leg.

3. The structure of claim 2 in which a flexible nonmetallic expansible water-tight shield completely invests said universal joint means and is itself protected by said guard shells secured at its ends to said guard shells.

4. In a through-transom drive, in combination with a boat hull having a transom and an inboard motor, a mounting member anchored to said hull forwardly of said transom and presenting a stationary hollow portion extending rearwardly through said transom, a hollow shell member turnably fitting into said hollow portion and occupying a position behind said transom, lock means for selectively locking said shell member relative to said mounting member, mounting apparatus having a pivotal mount on said shell member for fore and aft swinging movement toward and away from said transom, an outboard power leg carrying a propeller at its lower end and pivotally mounted on said mounting apparatus for lateral steering movement relative to said hull, and drive means for transferring power from said inboard motor through the hollow centers of said mounting member and shell member to said propeller via said power leg, said drive means including universal joint means located between the transom and the power leg extending through said mounting apparatus.

5. In a through-transom drive, in combination with a hollow forward housing fixedly associated with the hull of a boat and occupying an inboard position registering with an opening in the boats transom, an outboard power leg carrying a propeller at its lower end, a jointed hollow outboard housing comprising connected front and rear sections of which the front end of the front section is secured to the forward housing and extends rearwardly therefrom and the rear end of the rear section is rigidly attached to the power leg and extends forwardly therefrom and intermeshes with said front section, and a drive from an inboard engine passing through the hollow centers of the forward housing and said two sections of the outboard housing and connecting with a propeller-driving shaft in the power leg, means comprising the connection between said front and rear sections of the outboard housing being pivotally connected about a horizontal axis to said front section, said rear section being operatively pivotally connected about a vertical axis to said means and being so formed as to permit the rear section with its supported power leg to swing relative to the front section in both directions laterally about an upright axis for steering the boat and to tilt upwardly relative to the front section about a horizontal axis for raising the propeller, said swing axis sloping rearwardly in a downward direction and approximately transversing the tilt axis, cushion stop means being provided prescribing an upper extreme limit to which the power leg may be swung.

6. Structure according to claim in which the drive passing through said housing sections is sealed by an investing non-metallic expansion sleeve attached by one of its ends to the front housing section and by its other end to the rear housing section.

7. Structure according to claim 5 in which the drive comprises two shaft sections connected by a double universal joint, said universal joint being housed within said housing sections and being sealed against access of water by an investing non-metallic expansion sleeve attached by one of its ends to the front housing section and by its other end to the rear housing section.

8. Structure according to claim 5 in which the cushion stop means is carried by the outboard housing and is engaged at said upper limit of swing by the rear section of the outboard housing.

9. In a through-transom drive, a mounting member adapted to be mounted on a stern of a boat, said mounting member having a portion defining a central opening therein, power transfer shaft means adapted to be mounted to pass through said central opening in a fore and aft direction with respect to the boat, an outdrive assembly comprising an outboard power leg and an outboard power leg supporting member and an intermediate member, said intermediate member supporting said outboard power leg on said outboard power leg supporting member on a horizontal tilt-up axis With said power leg being connected with said intermediate member on a vertical steering axis, said outboard power leg supporting member being mounted coaxial with said power transfer shaft means and freely telescopically disposed in said central opening of said mounting member and being supported thereby, said outboard power leg carrying a propeller at its lower end and being operatively connected with said supporting member, locking means to selectively lock said supporting member with said mounting member in a longitudinal direction with respect to the axis of said power transfer shaft means or to release said supporting member from said mounting member for complete removal of said outdrive assembly from said mounting member, said locking means comprising a projecting means carried by said mounting member for movement laterally of said central opening in said mounting memto be pivotally mounted on the rearward portion of said mounting member for fore and aft swinging movement relative to said boat hull, an outboard power leg carrying a propeller at its lower end, said power leg being pivotally mounted on said mounting apparatus for steering movement relative to said boat hull, a first power transmitting shaft passing through said mounting apparatus, said first power transmitting shaft having an input portion and an output portion, a further power transmitting shaft passing downwardly through said power leg and operatively connected with said output portion of said first power transmitting shaft, flexible joint means operatively connecting said input portion and said output portion of said first power transmitting shaft, the steering axis of said mounting apparatus being substantially coincident with the working center of said flexible joint means and the pivotal axis of said mounting apparatus being substantially coincident with the working axis of said flexible joint means.

11. In a through-transom drive, in combination with a boat hull having a transom and an inboard motor, a mounting member fixedly associated with said hull and presenting a rearwardly open guard shell behind said transom, mounting apparatus having a pivotal mount on said guard shell for fore and aft swinging movement relative to the hull, an outboard power leg carrying a propeller at its lower end and pivotally mounted on said mounting apparatus for lateral steering movement relative to said hull, said power leg presenting a forwardly open guard shell meshing with the aforementioned guard shell, universal join-t means protectively housed in said guard shells, means for transferring power through said transom from said motor to said universal joint means and from the latter to said propeller via said power leg, and the shape of the two shells being such that the same collectively have much the appearance of a ball when viewed from above.

References Cited UNITED STATES PATENTS 1,028,333 6/ 1912 Desenberg 1l535 1,801,612 4/ 1931 Pierce. 1,890,938 12/1932 Fahrney 41 2,064,195 12/1936 Michelis 115-35 2,473, 618 6/ 1949 Stillwagon. 2,755,766 7/ 1956 Wanzer.

2,837,051 6/ 1958 Friedrich 11535 2,911,938 11/1959 Hulsebus 115-l7 FOREIGN PATENTS 340,367 8/ 1930 Great Britain.

MILTON BUCHLER, Primary Examiner.

EMILE PAUL, FERGUS S. MIDDLETON, Examiners.

R. D. BLAKESLEE, A. METCHELL, P. J. WALSH,

R. G. BESHA, T. MAJOR, Assistant Examiners. 

1. IN A THROUGH-TRANSOM DRIVE, IN COMBINATION WITH A BOAT HULL HAVING A TRANSOM AND AN INBOARD MOTOR, A MOUNTING MEMBER ANCHORED TO SAID HULL FORWARDLY OF SAID TRANSOM AND PRESENTING A HOLLOW PORTION EXTENDING REARWARDLY THROUGH SAID TRANSON, A HOLLOW REARWARDLY OPEN SHELL MEMBER INTERFITTING WITH SAID HOLLOW PORTION AND OCCUPYING A POSITION BEHIND SAID TRANSOM, MOUNTING APPARATUS PIVOTALLY MOUNTED ON SAID SHELL MEMBER FOR FORE AND AFT SWINGING MOVEMENT TOWARD AND AWAY FROM SAID TRANSOM, AN OUTBOARD POWER LEG CARRYING A PROPELLER AT ITS LOWER END AND PIVOTALLY MOUNTED ON SAID MOUNTING APPARATUS FOR LATERAL STEERING MOVEMENT ON SAID MOUNTING HULL, AND DRIVE MEANS FOR TRANSFERRING POWER FROM SAID INBOARD MOTOR THROUGH SAID MOUNTING MEMBER AND SHELL MEMBER TO SAID PROPELLER VIA SAID POWER LEG, SAID DRIVE MEANS INCLUDING UNIVERSAL JOINT MEANS LOCATED BETWEEN THE TRANSOM AND THE POWER LEG AND EXTENDING THROUGH SAID MOUNTING APPARATUS, SAID POWER LEG PRESENTING A FORWARDLY OPEN SHELL MEMBER WHICH INTERFITS WITH THE REARWARDLY OPEN SHELL MEMBER AND WITH THE LATTER PRODUCES A GUARD HOUSING INVESTING THE UNIVERSAL JOINT MEANS, SAID COMPOSITE GUARD HOUSING HAVING MUCH THE APPEARANCE OF A BALL WHEN VIEWED FROM ABOVE, THE PIVOT MOUNTING FOR THE MOUNTING APPARATUS BEING LOCATED ON A SUBSTANTIAL DIAMETER OF THE BALL. 